This invention relates to the field of animal running surfaces such as equestrian tracks, arenas, hot walkers, dog tracks, and the like. More specifically it focuses on a technique of optimizing the running surface with respect to several different characteristics. As an ancillary benefit to achieving its objectives, the invention--through its utilization of a common waste product--assists in the disposal of a particular waste product. Certainly most spectators of animal racing events assume that the tracks are simply soil. Until recently this was almost universally true. In creating such surfaces, minimal preparation was utilized. Vegetation was removed and the surface was periodically disked or graded to provide an even, smooth surface throughout the entire track. As the popularity of such racing events as horse racing or dog racing has increased, so has the focus on optimizing the event from many perspectives. Certainly the value of the animals has drastically increased. So too has the focus not only on optimizing their running potentials but also on minimizing any injury or stress forces that the animals experience.
Recently those skilled in the art of designing and maintaining animal running areas have realized that improvement of the surface itself was possible. Attempts have been made to mix a variety of items into the dirt at existing racetracks and arenas. Due to the nature of those involved in the sport, usually these efforts have involved farm by-products. These efforts have met with varying degrees of success. In some instances improvement may have occurred initially followed by a reduction in the quality of the running surface as the material decayed. In some instances the need to completely replace the surface as it has "worn out" may have occurred. As these types of limitations have become known, those skilled in the art of maintaining and constructing such surfaces have sought improved materials. Prior to the present invention, however, two approaches seemed available. Available material could be mixed into the dirt or the entire surface could be replaced by a synthetic surface. In mixing available material into the dirt a common item to use was wood chips. Not only can these increase the organic matter content, but they also decay relatively quickly. Unfortunately, these prior efforts had basically been the result of an unscientific "try-it-and-see" perspective. The long-term affects of these efforts are now being seen. Rather than merely considering the ease with which the surface is maintained, numerous other factors have come to the forefront. These factors differ in that they focus not on the maintenance crews' desires, but also on optimization of the surface for the animals themselves. The avoidance of injury and minimization of dust--although separately known to those skilled in the art--now are part of an integrated approach to surface construction and maintenance.
The present invention provides a new and improved technique for optimizing such surfaces. In doing so it not only greatly lengthens the time over which such surfaces remain effective, but it also provides a cost efficient surface. It departs from the approach of those utilizing wood chips in that a material which rapidly decays is specifically avoided. A particularly surprising aspect of the present invention is the fact that the material which provides this superior surface happens to also be available from a waste product--scrap tires. While efforts by those skilled in the art of constructing and maintaining animal running surfaces may have occasionally considered more highly processed materials, the present invention allows instead the utilization of a material whose disposal has been an unusual difficulty. This achieves two benefits at once.
Although efforts have been made to minimize the problem of waste tire disposal from a broad variety of vehicles, to date none of these efforts has met with great success. Certainly the rubber industry had attempted to develop uses for the waste product. As an example, the article "Scrap Tires Can Yield Marketable Products" published in 1973, explained efforts by a group called the Rubber Reclaimers Association (an industry consortium) proposed several different uses for the tires including mixing them into asphalt roads and providing crumbs as a foundation base below a house. Neither of these proposals has apparently met with great success. In 1986 a report entitled "Scrap Tire Recycling in California: A Status and Background Report" authored by the California Waste Management Board explained that of all the proposed disposal techniques, direct combustion was the most promising for eliminating the large numbers of scrap tires existing across the nation. Efforts by those focusing upon the disposal problem of scrap tires had even attempted to utilize shredded rubber for stabilization and growth enhancement of soils as detailed in "Evaluation of Combinations of Pine Bark, Peat, Shale, EKOL Leaf Mold, and Shredded Rubber in Growing Media". This article sharply contradicts the present invention in that it concluded that shredded rubber was not effective under certain soil chemical parameters for the desired result and thus rubber/soil mixtures should be avoided. The fact that those focusing on disposal of scrap tires never considered this application discovered by the present inventors underscores how separate and distinct the two fields are.
It should be understood that the present invention focuses upon the use of vulcanized rubber, not foam rubber and not natural rubber. Vulcanized rubber, although containing small amounts of natural rubber, is primarily a solid, non-porous, synthetic product. It differs markedly from foam rubbers and from natural latex rubber in these characteristics. Although efforts have been made to utilize these two products in soil combinations in other technical fields, their properties make them unsuitable with respect to the present invention. Similarly, efforts by those to utilize vulcanized rubber for other purposes have not led those involved in running surface construction and maintenance to consider this different application. As an example, U.S. Pat. No. 4,369,054 for a "Fiber/Slag Composition" focused upon the possibility of utilizing ground rubber in a broad variety of instances. None of these related to the peculiar needs of an animal running surface nor even generally to resiliency aspects.
Other efforts have focused upon playing surfaces. U.S. Pat. No. 4,564,310 for a "Resilient Paving Composition for Play Fields, Sports Fields and Recreation Areas" discloses the approach of providing an entirely synthetic surface. Although this patent did suggest using finely ground vulcanized rubber such as from scrap tires, the material was used in a manufactured surface. This surface was bonded with latex to provide the paving composition desired. It was not a loose soil surface as in the present invention. Similarly, U.S. Pat. No. 3,446,122 for "Elastic Surfaces for Sportsgrounds, Playgrounds and Footpaths" discloses an entirely manufactured surface which is separate from the dirt layer involved. The material used, polystyrene, is unlike the solid, vulcanized rubber used in the present invention and is not intermixed with earthen material. This is also true of U.S. Pat. No. 4,501,420 for "Playing Surfaces Sports". Although it used vulcanized rubbers such as from scrap tires, it provided a bonded, polymeric material which was not intermixed with earthen material and even had a synthetic turf overlayed upon it. Again, none of these patents disclosed a product which was appropriate for an animal running surface as contrasted to human playing surfaces.
Efforts have been made to improve animal running surfaces using a variety of techniques. In U.S. Pat. No. 3,203,396 for a "Method of and Means for Modifying Race Courses" the need for a resilient surface for a horse track was recognized. Rather than providing a technique for modifying a surface, that disclosure provided a means for separating the track to allow work on the compacted and worn out areas while the other area was used. Finally, in U.S. Pat. No. 4,819,933 for "All Weather Surfaces" the desire to provide a suitable equestrian surface using an intermixture of materials was disclosed. That recent invention focused upon a mixture of sand and synthetic fibers. The synthetic fibers were used in very small percentages (less than 1%) primarily to act as a binder to avoid any loose movement of the surface when in use rather than for resiliency. The present invention differs markedly in that binding of the surface layers is specifically avoided so that a loose surface as has historically been used is still possible.
The fact that there have been numerous efforts by those involved in the art of disposal of waste tires and the art of improving playing surfaces simply highlights the uniqueness of this application and the distinctness of the art of constructing and maintaining an animal running surface. In this field, efforts to mix a variety of by-products into a running surface had been done for years. These attempts, however, were inadequate because they failed to recognize the problem due to their failure to focus first upon the animals' needs rather than those of the maintenance crew. While recently those skilled in the art have begun to appreciate the need for an improved surface, they have not had available to them knowledge from unrelated fields such as that of tire disposal. Instead, their focus was directed primarily to what was at hand since it was understood by many that an acceptable solution could not utilize an "exotic" material while remaining cost effective. Until the present invention, those skilled in the art of racetrack construction, renovation, and maintenance simply did not have available to them a suitable product from the varied perspectives involved.
Apart from the particular material utilized, the present invention also presents methods which allow for the optimization of the surface to particular conditions. Given the limited focus of those involved in the construction and maintenance of animal running surfaces, this approach is a unique departure from the efforts of those skilled in the art. Prior to the present invention it had generally been assumed that one particular composition which was generally acceptable to a broad variety of conditions should be utilized. While the present invention provides for such a broad scale approach, it also presents methods which allow for optimization of the surface to accommodate the particular conditions encountered. In this fashion the present invention presents an approach heretofore unheard of by those skilled in the art of construction and maintenance of animal running surfaces.